Systems and methods to condition air
Systems and methods to condition air are disclosed. An example system includes a desiccant heat transfer device to supply conditioned air to a facility, an air intake to receive air to be conditioned via the desiccant heat transfer device, and a make-up exhaust to provide exhaust air from a heat dissipating device in the facility to provide heated air to reactivate the desiccant heat transfer device.
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Data centers and other facilities are provided with air conditioning systems to manage ambient temperatures and prevent overheating of electronic equipment. Such air conditioning systems are often costly and expensive to operate.
Commercial or industrial facilities, such as manufacturing facilities, data centers, and/or other types of facilities, often include large numbers of heat dissipating devices, each of which generates heat during operation. As used herein, heat dissipating devices may include computer or other electronic systems, machinery, or any other type of heat dissipating device. To reduce the risk of overheating, the heat dissipating devices are kept in air conditioned spaces and provided with fans to circulate air around the heat dissipating devices. Some known air conditioning systems cool outside air and provide the cooled air to the air conditioned space. These cooling systems can use significant amounts of resources such as electrical power. Facilities located in warmer, more humid climates particularly employ substantial amounts of electrical power to cool the air, which substantially increases the costs of operating such facilities.
Example systems and methods disclosed herein use waste heat from heat dissipating devices to reduce the energy load used to condition air for a facility in which the heat dissipating devices are located. A disclosed example system uses a desiccant heat transfer device, such as a desiccant wheel, to dry incoming air to be conditioned for a facility. Dry air uses fewer resources to cool to appropriate temperatures than air having higher moisture content. The desiccant wheel is then recharged by a combination of exhaust air from a heat source and make-up air from heat dissipating devices within the facility. Disclosed example facilities include data centers having heat dissipating devices such as computer systems. By providing exhaust air from a heat dissipating device in a facility to provide heated air for reactivating a desiccant heat transfer device, example systems and methods disclosed herein substantially reduce the high costs of operating facilities experienced by known systems. These operating costs are significantly reduced in relatively hot, humid climates.
The example system 100 of
In operation, the example air intake 108 receives the air to be conditioned and provides the air to the desiccant heat transfer device 102. The desiccant heat transfer device 102 at least partially conditions the air to generate conditioned air, which is provided to the example facility 104. In some examples, the conditioned air cools and/or dries the heat dissipating device(s) 106 to reduce or even prevent overheating and/or condensation. The heat dissipating device(s) 106 provide exhaust air to the make-up exhaust 110. The example make-up exhaust 110 provides heated air to the desiccant heat transfer device 102 to recharge the desiccant heat transfer device 102.
The example system 112 of
The example system 112 of
The example desiccant heat transfer device 102 of
After the air from the air intake 108 is conditioned by the desiccant heat transfer device 102, the air is output to the facility 104. In some examples, the desiccant heat transfer device 102 dries and cools the air prior to outputting to the facility 104. Drying the air from the air intake 108 reduces the energy load used by the desiccant heat transfer device 102 to cool or otherwise condition the air to a desired temperature. Additionally, combining air output by the heat dissipating device(s) 106 with the air from the make-up exhaust 110 reduces the energy used to generate heated air with the heater exhaust 114 to recharge the desiccant heat transfer device 102, thereby enhancing the recharging efficiency. Recharging efficiency is enhanced because the air output by the heat dissipating device(s) 106 is pre-heated by the heat dissipating device(s) 106 and previously dried by the desiccant heat transfer device 102.
The example desiccant heat transfer device 102 of
To provide conditioned air to the space 104, the example system 112 of
When passing through the adsorption area 208 and the desiccant wheel 202, an intake airflow 218 loses a substantial portion of its moisture to the desiccant material and, thus, drops in both relative and specific humidity. The resulting dried air 220 has lower relative humidity than the intake air 214 entering the air intake 108 and, thus, uses less energy to cool effectively. The dried air 220 is input to an evaporative cooler 222, which further conditions (e.g., cools) the dried air 220 and outputs conditioned air 224 to the facility 104. Within the example facility 104, the conditioned air 224 cools the heat dissipating device(s) 106 to reduce the risk of overheating.
The desiccant material within the example desiccant wheel 202 has a finite capacity for adsorbing moisture and, once saturated, cannot adsorb further moisture until at least some of the stored moisture is released. To release moisture from the desiccant material, heat is applied to the desiccant material, which causes the desiccant material to desorb the moisture. Heating the desiccant material to release contained moisture is also referred to herein as “recharging” the desiccant material in the desiccant wheel 202 and/or a section 204, 206 of the desiccant wheel 202.
A heat source 226 provides a source of heat to recharge the desiccant wheel 202. The example heat source 226 of
The example heat source 226 of
To provide air at the appropriate recharging temperature for the desiccant wheel 202, the example heat exchanger 230 transfers heat from the heated air 228 to the make-up air 232 to raise the temperature of the make-up air 232 to the recommended recharging temperature (or within a range of temperatures) for the desiccant wheel 202. The example heat exchanger 230 regulates the flow of make-up air 232 and/or the flow of heated air 228 to control the temperature of recharge air 234 to a desired desiccant recharging temperature.
In some examples, the heated air 228 is contaminated (e.g., with exhaust fumes), while the make-up air 232 is substantially cleaner and/or drier. To avoid contamination and/or loss of adsorption capacity of the desiccant material in the desiccant wheel 202, the heat exchanger 230 of
The recharge air 234 is forced through the desiccant wheel 202. As a result, the desiccant material desorbs moisture into the recharge air 234. Accordingly, recharge output air 238 exits a recharge output port 240. The recharge output air 238 has higher moisture content than the recharge air 236. The example recharge output air 238 is also cooler than the recharge air 234 due to the heat exchange with the desiccant material and the acquisition of additional moisture.
The intake air 214 entering the example air intake 108 of
The evaporative cooler 222 reduces the dry-bulb temperature of the dried air 220 and outputs the conditioned air 224. The conditioned air 224 is represented in
As illustrated in
To condition air for a facility (e.g., the facility 104, a data center, etc.), the example air intake 108 receives intake air 214 from an external environment (e.g., the external environment 216) (block 402). The example desiccant wheel 202 conditions (e.g., dries) the intake air 214 (block 404). For example, the desiccant material in the desiccant wheel 202 adsorbs moisture from the intake air 214. The example evaporative cooler 222 cools the dried air 220 from the desiccant wheel 202 (block 406) and outputs the cooled air 224 to the facility 104 of
The example method 400 iterates to continue conditioning air for the example facility 104. In some examples, the motor 212 rotates the desiccant wheel 202 for the duration of the example method 400. The method 400 is an example conditioning process for a given volume of air entering the example air intake 108 of
To recharge an example desiccant heat transfer device 102 (e.g., the desiccant wheel 202 of
The example method 500 iterates to continue recharging the example desiccant wheel 202 of
The example method 600 begins by drying intake air using a desiccant heat transfer device (e.g., the desiccant heat transfer device 102 of
The example method then supplies the recharge air to the desiccant heat transfer device 102 to recharge the desiccant heat transfer device 102 (block 606). The recharge air causes a desiccant material in the desiccant heat transfer device 102 to desorb moisture, which recharges the desiccant material. Recharging the desiccant material frees at least a portion of the capacity of the desiccant material to adsorb moisture, and enables the desiccant heat transfer device 102 to adsorb further moisture. The example method 600 may then end and/or iterate to continue conditioning air.
From the foregoing, it will be appreciated that the example systems and methods condition air (e.g., air for a facility such as a data center) using fewer resources than known air conditioning systems. The decrease in resource consumption is particularly significant in hot, humid climates.
Although certain methods, apparatus, and articles of manufacture have been described herein, the scope of coverage of this patent is not limited thereto. To the contrary, this patent covers all methods, apparatus, and articles of manufacture falling within the scope of the claims.
Claims
1. A system to condition air, comprising:
- a desiccant heat transfer device to supply conditioned air to a facility;
- an air intake to receive air to be conditioned via the desiccant heat transfer device;
- a make-up exhaust to provide exhaust air from a heat dissipating device in the facility to provide heated air to reactivate the desiccant heat transfer device; and
- a heat exchanger to transfer heat between the heated air and the exhaust air and to provide heated exhaust air to recharge the desiccant heat transfer device.
2. The system of claim 1, wherein the air intake is to receive air from an environment external to the facility center.
3. The system of claim 1, wherein the desiccant heat transfer device is to adsorb moisture from the received air.
4. The system of claim 1, wherein the desiccant heat transfer device comprises a desiccant wheel and a motor to rotate the desiccant wheel.
5. The system of claim 1, further comprising a cooling device to cool the conditioned air from the desiccant heat transfer device.
6. The system of claim 1, wherein a reactivation temperature of the heated exhaust air is sufficient to cause a desiccant material in the desiccant heat transfer device to desorb moisture into the heated exhaust air.
7. The system of claim 1, wherein the heat exchanger is to keep the heated air and the exhaust air physically separated.
8. The system of claim 1, further comprising a heater exhaust to provide the heated air from a heat source.
9. The system of claim 1, wherein the heat exchanger is to combine the heated air and the exhaust air.
10. A method to condition air, comprising:
- drying intake air using a desiccant heat transfer device;
- generating recharge air from exhaust air from a heat dissipating device by transferring heat between heated air and the exhaust air via a heat exchanger; and
- supplying the recharge air to the desiccant heat transfer device to recharge the desiccant heat transfer device.
11. The method of claim 10, wherein generating the recharge air comprises transferring heat from the heated air to the exhaust air.
12. The method of claim 11, further comprising keeping the heated air and the exhaust air physically separated.
13. The method of claim 10, wherein generating the recharge air comprises combining the exhaust air with the heated air.
14. The method of claim 13, wherein the heated air comprises exhaust air from a power generation device.
15. The method of claim 10, wherein the exhaust air comprises exhaust air from a plurality of computer systems in a data center.
16. The method of claim 10, further comprising rotating the desiccant heat transfer device to move a first section of the desiccant heat transfer device from an adsorption stage to a recharging stage and to move a second section of the desiccant heat transfer device from the recharging stage to the adsorption stage.
17. The method of claim 10, further comprising cooling the intake air after drying the intake air.
18. The method of claim 10, further comprising outputting the dried air to a facility containing the heat dissipating device.
19. The method of claim 18, further comprising receiving air from an environment outside the space.
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Type: Grant
Filed: Jul 29, 2011
Date of Patent: Feb 4, 2014
Patent Publication Number: 20130025450
Assignee: Hewlett-Packard Development Company, L.P. (Houston, TX)
Inventors: Ratnesh Kumar Sharma (Fremont, CA), Chih C. Shih (San Jose, CA), Thomas W. Christian (Fort Collins, CO), Cullen E. Bash (Los Gatos, CA)
Primary Examiner: Frank Lawrence, Jr.
Application Number: 13/194,123
International Classification: B01D 53/06 (20060101); B01D 53/26 (20060101);